Pond Boss Forums AERATION Systems questions Got a few Questions for y'all...

Hi again!

As I mentioned in my intro post a few days ago, my 2 ponds are 7/10 acre and 4/10 acres respectively. Neither pond has ever been aerated.

They are around 70 years old, and are lined with trees. Every fall the surface is blanketed with fallen leave that eventually sink to the bottom and over time have contributed significantly to the muck at the bottom. Over the decades the ponds have gotten shallower due to this buildup of muck. The deepest area of either pond is probably in the 6 foot range, possibly 6 � at the most. The water is dark green with low visibility and during the hottest days of summer (like right now) a film of pond scum occasionally covers a portion of the surface. Overall they are somewhat stagnant. The fishing is great, typically, but swimming is not something you�d want to do. We used to swim in them as kids, and always got a big laugh when we would climb out and the algae sticking to the hairs on our arms and legs gave us a comical caveman look.

I have been reading the forum over the last few days regarding aeration, as it seems like that should be my first order of business in any effort to improve the condition of these ponds. From my reading, I think I am leaning toward a bottom air diffusion aeration system of some sort due to the costs verses efficency. My wife would love a fountain aerator for aesthetic reasons, but I am all about cost. I want something that will give me the most bang for buck and air diffusers seem to fit that bill, especially in monthly operating costs. Not to belabor the point, but our household budget is extremely strained at this point for reasons I won�t go in to. I�m asking these aeration questions for future reference actually because I don�t see myself installing anything until next spring at the earliest unless there are some relatively inexpensive DIY designs out there I could attempt.

My questions are as follows for any of you folks that know about such things;

Firstly, what can I possibly expect? I know every pond is different, and that�s a hard one to answer, but I�m looking for a general overview. I�m trying to provide the most info I can to help the educated guesses any of you might provide. Assuming I get the DO levels correct and the pond de-stratified, how dramatic will the improvement be compared to what it is now? What I�m mostly hoping for is a reduction in the muck and improved water clarity. Is this a reasonable hope? My fish seem in good health and that has been the case for many years. As my initial post explained, I did have one fish kill event years ago, but I think that was brought about by an overstocking of CC, and it hasn�t happened since.

Second question; What system should I get? I�m very handy and love messing with mechanical things. Are there any good do it yourself plans out there that can deliver the goods at minimal costs? If not, who sells the most value packed systems? Will one diffuser in each pond do the trick? Can one pump handle both diffusers, etc?

Third question; it�s sort of a repeat of the first question. I would love to get most of the muck out of my ponds. Dredging is obviously cost prohibitive and I�ve read conflicting results of the effectiveness of aerating to help the bacterial decomposition of the muck in a pond. I would love to add some beneficial bacterial the speed up the process, but I got time more than money so will aerating eventually get me there, even if it takes 5 years? Remember than the majority of the muck comes from leaves rather than runoff so it would seem it would be dissolvable by bacteria.

Thanks in advance for any advice,
Ponduke

I'm not an aeration expert but have an bottom diffuser aerator.

Your shallow depth stands out. I wouldn't think there would be much if any stratification in a 6' deep pond in S. IN. Bottom diffusers are usually better for ponds deeper than yours. There are some shallow water bottom diffusers out there now though that would be worth a look.

What can you expect? Well, I saw clarity increase within a few days. Some pond owners have actually had their clarity reduced due to turbidity or algae blooms from nutrients released.

Muck reduction from bacteria and/or aeration results are all over the place. Some people see great results some people see none.

I'm pretty handy and frugal. I seriously considered and researched building my own system. After estimating material costs, considering the expected end product looks and function I bought a tested, proven, well reviewed system. I estimate it probably only cost about 25% more than what I could have assembled one for (not including my time)but I feel I ended up with something that looked better, probably functions better, had a warranty and customer support.

Thanks for the quick reply. I wondered about the depth, or lack thereof, in my ponds. If you are correct and there is little to no stratification, then am I correct to assume that I will see little to no reduction in the depth of muck over the years as the aerobic bacteria already likely have sufficient DO to do their work? Maybe I will consider a fountain aerator after all, but I assume those cost more in electric consumption. Is this correct, typically?

I think you will benifit from reading thru this
http://www.omegalakeservices.com/The_Guide_to_Opitum_Pond_Dynami.html

Look thru the page helpful links alot off good stuff there as well.
I think maybe you should consider mecanical removal off the muck, aeration alone with 70 years off build up will take a long long time.

From my experience, all I can say is whatever system you go with, use the self-sinking air hose from the start.

You should probably check out the suface agitator aerators that are commonly used at fish farms. Here's a link with pricing and operating costs http://www.dunnsfishfarm.com/kasco_pond_aerators_61_ctg.htm They're not really a decorative fountain but purpose built for maximum oxygen transfer. I would also compare to the shallow water diffuser systems. For small systems, operating cost differences betweeen bottom diffusers and surface agitators seem minimal.

You should talk to Rainman about tilapia stocking there have been ponds that have actually gained significant depth from the tilapia's feeding action. They eat the bacteria that is breaking down the detritus on the bottom of the pond, and also a significant amount of the actual detritus as well. As an added benefit their constant foraging will help to turn the bottom debris, speeding its decomposition. Hopefully Rex will chime in here, and explain it a bit better. I believe he stocked a pond in Tennessee that gained significant depth in a single season. After I stocked them in my pond I had a heavy algae bloom, that I am primarily attributing to the release of nutrients locked up in detritus from the tilapia's feeding action. The bloom lasted heavily for a couple weeks, and has now died down a bit. Check into it, they might be worth a try to gain some depth?

Tilapia you say? Hmmm... This sounds intriguing. I have seen reference to tilapia on the forum, but considering I am brand new here I hadn�t really investigated this potential option to improving my ponds. I will research further. If anyone knows of any studies or real world examples of the effectiveness of tilapia for muck reduction in a pond let me know. The added bonus of food for my LMB and even my family is pretty exciting as well. I have read that the blue tilapia (the kind I should get I�m assuming) die when water reaches below 45 degrees so I guess I would need to stock them as soon in the spring as possible when the water warms up enough and then catch as many as possible when the water starts to dip close to 45 degrees in the fall. Is that correct? I would need to restock every year then I guess? I�m going to look into this further. Thanks for the suggestion.

>55 degrees is closer. 60deg. is even better. They won't eat much when the water is cold anyway, not worth chancing a die off. I've stocked tilapia as early as late April but late June is probably better. S. IN is usually a week or two ahead of my place on temps in the Spring. I can't say from personal experience about muck reduction but they will eat their own waste readily. I've seen where they put tilapia in the filter tank of a RAS to help keep the filter clean.

Ponduke, Blue tilapia die at ~45*, but in a pond situation, that is a little misleading. Blue Tilapia start getting lethargic ~58* as well as depressing their immune systems. With predators present, except for the largest, Blues are more likely to die from injury/infection/predation before the water temps drop to lethal levels. For LMB, Blues become an easy target when the LMB's metabolism has slowed allowing the Tilapia they gorge themselves on to turn into lipds rather than muscle. This allows the LMB to have greater fat stores to live on during the winter, resulting in less weight/flesh loss over the winter.

There are few "scientific" studies on tilapia outside of the food fish industry. Hopefully this fall that will begin to change. There are many reports and studies that are related to tilapia consuming what we call "muck"---detritus. It must be organic in nature and have nutients that are digestible though.

Thanks for the info Rainman.

I am even more intrigued by the idea of introducing tilapia into my ponds next spring. I initially was only intersted in the muck reduction potential, but the added benifits of LMB food, weed control, etc. are pretty cool in their own right.

But, back to the muck, which started this avenue of research. Considering that the lionshare of the muck would have derived from dropped leaves from the tree's the line the ponds and very little would be from inorganic silt from runoff, etc. since there is little in the way of a watershed for either pond, would this, at least initially, indicate to you that my particular muck situation would potentially be a good candidate for seeing some reduction of muck over some years with the introduction of tilapia in significant numbers each spring? if so, what might be a good number of pounds per pond to stock from your experience? (7/10 acre and 4/10 acre)

Ponduke

Ponduke, yes leaf detritus is a favorite for tilapia to consume! BUT, I'll make the assumption that at 70 years old, you pond has a lot of predators. This situation may make stocking tilapia a futile effort in muck reduction.

If your ponds have not been well managed over the years and they have lots of stunted apex predators, it may take an unreasonably high stocking rate to clear significant amounts of detritus. The cost of a complete renovation and restocking may well cost you less.

If your pond has a balanced population with few, but larger apex predators, 100 pounds of mixed sex tilapia would most likely make a very significant reduction in the depth of detritus.

There are a lot more variables that enter in to the best equation for stocking tilapia to make any solid suggestion.

Tilapia are eating machines, but larger ones spend a large amount of time spawning instead of eating. It's the vast number of mouths on the extremely fast growing offspring born about every 3 weeks that make the biggest impact on detritus and plant reduction in ponds stocked annually. In a pond with many predators of any kind, few offspring make it past 2 inches long before getting eaten.

You will have to overwhelm predators with enough adult tilapia in order to produce more offspring than your predators can eat to get dramatic reduction in much depth.


I also need to mention tilapia will eat what THEY want, not just what we want them to eat. If you have plants that you want to keep AND you want dramatic reductions in muck....forget about anything green as it will disappear in short order with high tilapia stocking rates.

Last year a customer in Shelbyville Ky. stocked 600 3-5 inch tilapia in a one acre pond with NO OTHER FISH PRESENT for duckweed control. The tilapia did not keep up with the duckweed, but after heavy runoff and wind flushed the duckweed out of the pond, the tilapia were able to prevent it's return. This pond owner does not care about the pond other than for aestethics and rarly looks at it up close. When cool weather hit and he noticed wildlife eating dead tilapia, he went to inpect his pond. The water was crystal clear and had never been more than 4 feet deep...filled with detritus. He told me he looked at the pond and was amazed to see a red clay bottom everywhere...not a black "muck" patch in sight! He got in his boat and was unable to reach the bottom with his paddle anymore and estimated the depth at over 8 feet now. He went with only 10 pounds this year in hopes to keep duckweed from returning and for insect control.

In my opinion, without seeing your pond first, your BEST solutions for removing the detritus would be either a complete renovation, or adding a QUALITY aeration system. Adding tilapia annually would greatly speed the breakdown of the detritus with an aeration system where predators are present.

Excellent response and much appreciated Rainman! Good points all. I do indeed have a significant amount of predator fish in both ponds. I knew that might be a big problem, just wasn't sure how big. I am going to aerate in the future, when funds allow. Complete renovation is not feasible money wise and likely wont be for some time, so that's off the table for the forseeable future.

The Shelbyville example is exactly what I'm after. I want the pond cleared up to a more pristine state. I'm not concerned with other vegitation being eaten as well by any tilapia I stock. I would even consider clearing the predator fish and starting over after the tilapia had done the sort of make over you cited in your example. Lots of things to consider here.

My whole life these ponds have been a dark murky green with to-your-knees muck and I would really love to one day see clear water and a firm bottom. If aeration along with tilapia is potentially a way to do it, I will keep that option viable, even if it means killing off all my current predators. (How it that typically done by the way, if you know?)